>(1) Anatoxin-a is one bad dude. It kills mice in microgram > quantitites. I would add that some of the most potent toxins known to man are produced by micro-organisms, particularly those that live on decaying produce. There is a reason for this, in that it is to the advantage of these species to kill off larger competitors to their food supply. Botulism, gray molds on breads, aflatoxin (widespread on peanuts, corn & other crops which are harvested in warm, humid climates) & other such nasties either can kill outright or are powerful carcinogens. --Doug Schwartz [log in to unmask]